1. Field of Invention
The present invention relates to a fan, and more particularly to a fan heater which comprises a plurality of blade assemblies for minimizing the weight and the manufacturing cost of the fan heater.
2. Description of Related Arts
A conventional fan heater is usually a compact electrical household appliance, which heats the room by drawing air to go through a plurality of electrical heating elements, such as heating wires, provided within the fan heater.
A typical fan heater usually comprises a heater body, a fan, a heating element, and a power unit electrically connecting the heating element and the fan with a power source. The heater body usually has an air inlet, an air outlet, and a receiving cavity formed within the heater body to communicate between the air inlet and the air outlet, wherein the heating element is mounted in the vicinity of the air outlet. The fan is rotatably mounted with in the receiving cavity in such a manner that when it is activated, it will rotate to draw air from the air inlet, and force air out from the air outlet via the heating element. Thus, at the same time the fan is being driven to rotate, the heating element is electrically conducted to generate heat, so that the air which is forced to blow out from the air outlet is first pushed to thermally communicate with the heating element before it is blown out from the air outlet. The result is that the air coming out from the air outlet is heated to a predetermined temperature according to the elevated temperature of the heating element.
The fans used in convention fan heaters can broadly be divided into three major types according to the mechanical structure of the fans used and the position of the air inlets and the air outlets. First, there exists radial flow fan which is capable of delivering air flow in radial direction with respect to the fan. Second, there exists axial flow fan which is capable of drawing air flow along an axial direction of the fan. Finally, there exists centrifugal fan in which the inflow air is ninety degrees with respect to the outflow air. Accordingly, the air inlet and the air outlet are formed at the corresponding positions on the heater body.
A main problem for these conventional fan heaters is that the fan, no matter which kind is it, is usually made of metallic materials which, although strong and durable, are very heavy. As a result, conventional fan heaters are usually bulky in size, and heavy in weight. This makes conventional fan heaters extremely difficult to carry and transport. Moreover, since the heater fan blades are made of metallic materials, when the fan is rotating within the heater body, the heavy heater fan blades will induce substantial vibration to the entire heater body as well as other components of the fan heater. The result is to make the fan heater very noisy when it is operating.
Furthermore, most of the fans mounted within the receiving cavity are manufactured as separate integral pieces which increase the difficulty for securely mounting onto the respective heater body in rotatably movable manner. Thus, conventional process for manufacturing fan heaters involves expensive manufacturing machines and complicated steps. These in turn have contributed to the elevated selling price of conventional fan heaters, and prohibited a widespread application of fan heaters.